Practice shell



Jan. 2, 1968 H. GAWLICK ET AL 3,361,066

PRACTICE SHELL Filed Dec. 13, 1965 INVENTORS HEINZ GAWLICK RUDOLF STAHLMANN BY M 4?) ATTORNEYS United States l atent C D 4 12 Claims. Cl. 102-87) ABSTRACT (IF THE DISCLOSURE The present disclosure relates to a practice projectile having a central opening aperture containing therein a forward impact fuse, an adjacent smoke producing charge, an adjacent piston, and an adjacent tracer producing charge. Upon firing the projectile from the Weapon, the tracer charge is ignited to give a visible trace of the trajectory. When the projectile strikes the target, the impact fuse is ignited to in turn ignite the smoke producing charge, which produces high pressure gases to drive the piston rearwardly and out of the central aperture so that all remaining portions of the tracer composition are discharged loosely and unconfined for dispersion in the air where they cannot start accidental fires.

With artillery practice shells there exists frequently the desire to observe the flight path or trajectory and the impact place of the shell or projectile in order to be able to draw therefrom conclusions concerning the training progress of the gunners, the course of battle practices and the like. Accordingly, the practice shells used in those cases for firing purposes are equipped with a tracer composition charge for rendering visible the flight trajectory and with a smoke composition charge for rendering visible the place of impact. Since the tracer composition charge is to be ignited already during firing for the purpose of achieving a tracer path indicating the flight trajectory whereas the smoke composition charge is to be ignited only upon impact of the shell for purposes of marking the impact place, it follows that the tracer composition charge is accommodated in the rear part of the shell and the smoke composition charge together with the associated percussion fuse or impact detonator is accommodated within the shell in front of the tracer composition charge.

During firing of practice shells of such construction, it is quite possible that the shell strike and the smoke composition charge is ignited already before the tracer composition charge has burnt out. Analogously, it may happen that the tracer composition charge burns out only in the shell or projectile when the same is already on the ground. If the tracer composition charge is pressed in the usual manner into a case, closed on one side with a securely arranged bottom, for example, formed thereon, and is inserted by means thereof into the practice shell or projectile with the bottom facing forwardly, it may also happen, insofar as no separate lateral discharge apertures are provided in the shell body for the discharge or escape of the gases of the smoke composition charge, that the tracer composition case is ejected and thrown out toward the rear of the shell together with the stillburning tracer composition charge by the pressure of the developing gases of the smoke composition charge. This may happen, even if the tracer composition case is pressed more or less rigidly into the shell and is additionally secured in the same by means of a cap, clamped or wedged onto the rear end thereof. In one as in the other case, particularly however in the last-mentioned case, i.e. during an ejection and subsequent flying-away 3,361,066 Patented Jan. 2, 1968 of the hot tracer composition case with a still burning tracer composition charge, there exists the great danger within the impact area in the presence of easily ignitable objects and materials such as dry underbrush, leaves, or the like of the starting of fires which are to be avoided insofar as possible.

The ejection of the tracer composition case out of the shell may be prevented by the aforementioned known measure of the arrangement and construction of lateral escape apertures for the gases of the smoke composition charge and therewith the greatest first danger may be eliminated. The completely satisfactory functioning of such lateral gas discharge apertures is, however, jeopardized at least if the shell is strongly deformed during impact on, for example, hard rocks or the like which may be the case above all with the small caliber practice shells made for the most part of relatively soft material such as lead or lead alloy, or if the shell should bore very deeply into soft terrain. correspondingly, the reduction of fire hazard by the arrangement and construction of lateral gas discharge apertures in the shell body would be synonymous with the acceptance of other disadvantages and uncertainties whence such measures cannot completely satisfy.

The purpose of the present invention resides in providing a solution for practice shells having an axial aperture starting from the rear end and provided in this aperture with a percussion fuse, a smoke composition charge to be ignited by the percussion fuse and a tracer composition charge to be ignited during firing-arranged one behind the other when going from in front to the rearwhich solution not only eliminates any danger of the possibility of fires by the tracer composition charge but simultaneously therewith assures also the particularly advantageous and appropriate escape of the smoke produced by the smoke composition charge out of the rear end of the shell. The solution according to the present invention essentially consists in the proposal to separate the smoke composition charge and the tracer composition charge by an easily ejectable bottom adapted to be easily ejected toward the rear, Whose cross section on the side of the tracer composition coincides with that of the tracer composition. Appropriately, the arrangement and construction of this bottom is also made in such a manner that the cross section on the side of the smoke composition corresponds approximately to that of the smoke composition.

In order not to be forced by the arrangement of the separating bottom to predetermine unequivocally the shell for only one certain application or use, it is additionally recommended according to the present invention to accommodate the smoke composition charge and tracer composition charge in a common case or also in two separate cases directly adjoining one another, and to insert the same by means of this case or cases into the shell whereby additionally not only the laboratory Work of the compositions is simplified but also the possibility exists to provide the shell without or also with only one or the other composition and to fire the same or to prepare the shell in relatively short time in the desired or required manner.

In order to assure a good and tight separation between the two compositions, notwithstanding the requisite easy ejectability of the bottom, and to keep also the bottom safely in the desired or required position, it is advantageous to provide the same with a shoulder-shaped step by means of which it supports itself within the latter or within the cartridge case in the direction toward the forward end of the shell.

The bottom may be made in a particularly appropriate manner of a powder-like inert mass in that the inert mass is pressed-in during the laboratory work of the compositions in a corresponding manner or is prefabricated into a blank and inserted as such into the shell. One aims at and also achieves thereby that the bottom is decomposed, after the ignition of the smoke composition charge, by the pressure produced during burning thereof into its powdershaped component parts and is correspondingly more readily ejected and atomized or pulverized, together with the remainder of the tracer composition charge.

Accordingly, it is an object of the present invention to provide a practice shell of the type described above which avoids by simple means the shortcomings and drawbacks encountered with the prior art constructions.

It is another object of the present invention to provide a practice shell containing a tracer composition charge which eliminates the fire hazards in case of incomplete burning of the tracer composition when striking the ground.

A further object of the present invention resides in the provision of a practice shell containing both a tracer composition and smoke composition charge which assures proper burning of the smoke composition charge upon impact of the shell on the ground while causing the residues, if any, of the tracer composition charge to be ejected out of the shell in such a manner as to reduce the fire hazards.

A still further object of the present invention resides in the provision of a practice shell having a smoke composition charge and tracer composition charge which assures proper operation and functioning of the respective charges in proper timed relationship.

Still a further object of the present invention resides in a practice shell of the type described above which permits great versatility in the use and application of the shell.

These and further objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

The single figure illustrates an axial cross-sectional view through a small caliber practice shell adapted to be fired from a liner in accordance with the present invention.

Referring now to the single figure of the drawing, reference numeral 1 designates therein the practice shell made, for example, of lead or lead alloy and provided with rear and forward guide rings 3 and 4, respectively, which is inserted into a cartridge or shell case 2 extended up to the forward guide rings 4. The propellant charge 6 and primer 7 are arranged in the bottom of the cartridge or shell case 2. The practice shell 1 is provided within its axial recess, lined by means of the reinforcing case S and going from in front to the rear, with an im pact fuse 9, with the smoke composition case 10 having an ignition channel 11 and containing the smoke composition charge 12 and with the tracer composition case 13 containing the tracer composition charge 14.

The smoke composition charge 12 and the tracer composition charge 14 are separated from one another by the bottom or piston 15 which at the same time represents the bottom of the tracer composition case 13 and is supported within the latter by means of the shoulder-shaped step 16 formed by the collar or flange-shaped extension against the forward end of the shell 1 in such a manner that the bottom 15 is retained in its position toward the front but can be ejected toward the rear whereby it is clear, of course, that it has to be correspondingly matched for that purpose to the case 13 as regards shapes and dimensions of its cross section. The reinforcing case 8 as well as the parts arranged therein are secured against falling out by means of the cap 17 appropriately secured on the rear end of the shell 1, for example, by being pressed thereon, clamped thereon or also retained thereon by a plug or threaded connection.

Upon impact of the practice shell 1, at first the impact fuse 9 ignites the smoke composition charge 12 by way of the ignition channel 11. The bottom 15 is ejected toward the rear out of the case 13 or out of the shell 1 by the pressure produced by the burning of the smoke composition charge 12, whereby eventually any not yet burned out or still burning parts of the trace compo sh tion charge 14, which were ignited already during firing of the shell 1 and which are still present within the case 13 and have not yet burned out or are still burning, are ejected toward the rear and are thereby pulverized so that, on the one hand, a fire hazard is avoided and, on the other, the smoke of the smoke composition charge can now leave into the atmosphere unimpededly through the now empty case 13 and can thereby become visible.

While we have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art. For example, it is understood that the form and construction of the shell can be varied in numerous ways without in any Way aflfecting the principle of the present invention. Thus, neither the forward guide rings 4 nor the cartridge extended up to these guide rings 4 are a prerequisite; as a matter of fact, a cartridge case is not necessary at all. Similarly, no particular reinforcing case is necessary insofar as the shell is made of a material having sufiiciently large rigidity. T herebeyond, it would also be feasible to dispense with the smoke composition and/or the tracer composition case 10 and 13, respectively, and to install the smoke and/ or tracer composition charge 12 and 14, separated from one another by a bottom, to the rear of the impact fuse 9 directly into the reinforcing case or even directly into the aperture of the shell body. However, it is essential that the bottom 15, on the ejection side thereof, corresponds approximately to the cross section of the tracer composition charge 14 so that the latter is completely ejected and pulverized, which is assured in particular when during the ejection of the bottom 15 a more or less large wiping effect occurs between the bottom 15 and the surrounding walls of the case or shell, which can be readily achieved by a corresponding dimensioning of the parts. In order to achieve a completely safe and certain ejection of the entire tracer composition charge, it is also of signifiicance that the aperture 18 of a securing cap 17 provided on the rear end of the shell is chosen so large that the cap 17 projects at no place into the cross section of the tracer composition charge 14 or of the ejection side of the bottom 15. On the other hand, the manner of securing of such a cap is without significance; for this can be achieved in a completely satisfactory manner in numerous ways, completely apart from the fact that the good and safe securing of any used cases may also be achieved without difliculty by dispensing with such a cap.

Thus, it is obvious that the present invention is not limited to the details shown and described herein and we therefore do not wish to be limited to these details but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

We claim:

1. A practice projectile for firing from a weapon through a trajectory to impact upon a target and having an axis, a front end and a rear end, with respect to the trajectory, comprising: a projectile body; tracer composition charge means within said body for burning to produce a visible tracer products trail of the trajectory; smoke composition charge means within said body for ignition to produce a visible smoke products signal of the target impact location; fuse means within said body for igniting said smoke composition charge means upon impact of the projectile at the target; ejection means within said body for actuation upon impact of the projectile at the target for rejecting substantially any remaining portions of said tracer composition charge means loosely and unconfined from said body for dispersement.

2. The projectile according to claim 1, wherein said body has internal side walls forming a substantially axially extending aperture opening rearwardly; said fuse means, smoke composition charge means and tracer composition charge means being arranged serially front to rear in said aperture, respectively; said ejection means including a piston between said tracer composition charge means and smoke composition charge means and engaging said body side walls to form therewith an expandible Working chamber forwardly of said piston having therein said smoke composition charge means, said Walls to the rear of said piston having substantially the same cross sectional configuration as said piston perpendicular to the axis and engaging said tracer composition charge means, and said smoke composition charge means driving said piston rearwardly out of said aperture upon ignition thereof for wiping said side walls of said tracer composition charge means.

3. The projectile according to claim 2, wherein said piston has a cross sectional area perpendicular to the axis on the side of said smoke composition charge means that at least approximately equals the adjacent corresponding cross sectional area of said smoke composition charge means.

4. The projectile according to claim 2, wherein said wall means includes a single substantially tubular case having therein said smoke and tracer composition charge means; said piston is a separate plug within said case.

5. The projectile according to claim 2, wherein said side walls include a separate substantially tubular case for each of said smoke composition charge means and said tracer composition charge means, respectively, arranged axially aligned with respect to each other; said piston is a separate plug within said case.

6. The projectile according to claim 5, wherein said side walls form a rearwardly axially facing shoulder; said piston having a forwardly facing shoulder engaging said side wall rearward facing shoulder.

7. The projectile according to claim 2, wherein said piston consists of a compacted self-sustaining powder readily disintegrateable upon ejection from said aperture.

8. The projectile according to claim 3, wherein said wall means includes a single substantially tubular case having therein said smoke and tracer composition charge means; said piston is a separate plug within said case.

9. The projectile according to claim 3, wherein said side walls include a separate substantially tubular case for each of said smoke composition charge means and said tracer composition charge means, respectively, arranged axially aligned with respect to each other; said piston is a separate plug within said case.

10. The projectile according to claim 9, wherein said side walls form a rearwardly axially facing shoulder; said piston having a forwardly facing shoulder engaging said side wall rearward facing shoulder.

11. The projectile according to claim 3, wherein said piston consists of a compacted self-sustaining powder readily disintegrateable upon ejection from said aperture.

12. The projectile according to claim 2, wherein said side walls form a rearwardly axially facing shoulder; said piston having a forwardly facing shoulder engaging said side wall rearward facing shoulder.

References Cited UNITED STATES PATENTS 2,900,914 8/1959 Ciccone 10287 X 3,013,495 12/1961 Stevenson et al. 102-60 X 3,101,054 7/1963 Stevenson et al 10260 3,236,184 2/1966 Stadler et a1 102-92.5

BENJAMIN A. BORCHELT, Primary Examiner. ROBERT F. STAHL, Examiner. 

